1. Field of the Invention
The invention relates to body implantable devices and materials.
2. Description of Related Art
When devices or materials are implanted in an organism, the body's own immune system starts a defense reaction as soon as the implant is recognized as foreign. Since during an implantation, the surrounding tissue is usually damaged, injured or considerably altered, additional bleeding occurs causing thrombi [blood clots] to be formed. The disintegration of these thrombi then initiates the formation of connective tissue. The thickness of the connective tissue layer depends on the biocompatibility of the implant and on the extent of trauma to the surrounding tissue.
The thickness of connective tissue layers could be diminished by reducing the formation of thrombi or by causing them to disintegrate. Thus, one could improve the functioning of implants whose operativeness is adversely affected by connective tissue. For example, in the case of stimulating electrodes for pacemakers, attempts have been made to reduce the defense reaction of the body, that is the formation of connective tissue layers by using asteroid such as Cortisone or Dexamethasone (c.f.: U.S. Pat. No. 5,103,837). However, these medicines are not specifically effective with regard to the formation of thrombi and the reduction of connective tissue growth; an overdose could even cause unwanted side effects.
The object of the invention is to provide body implantable devices and materials wherein the formation of thrombi and connective tissue is prevented or reduced in connection with the implantation thereof.